Removable platen support



h 1,625,891 l mganl 26, 1927. o. A. HOKANSON REMOVABLE PLATEN SUPPORT Filed July 19. 1924 2 Sheets-Sheet '1 April 26, 1927; 1,625,891

0. A. HOKANSON' REMOVABLE PLATEN'SUPPORT Filed Julyl9. 1924 2 Sheets-Sheet 2 ju /7751".- W 6 Patented Apr. 26, 1927.

UNITED STATES.

o'r'ro A. HOKANSON; or woons'rooK, ILLINOIS, asslenon To woons'roox TYPE- h6Z'5,89l

PA-T E N T QF-FLQ WRITER, COMPANY, OEWQODSTOCK, ILLINOIS, a oonronerron on ILLINois.

REMOVABLE PLATEN SUPPORT.

Application filed July 19, 1924.

This invention relates to mechanism for retaining the platen in. position on a typewriter carriage, and hasfor its object the. provision of such retaining means which shall permit ready removal of the platen.

The invention is exemplified in the comhination and arrangement of parts shown in the accompanying drawings anddescribed in the following specification, andit is more particularly pointed out in the appended claims.

In the drawings,

Fig. l is a front elevation with parts broken away of a portion of a typewriter carriage showing one embodiment of the present invention.

Fig. 2 is a section. substantially on line of Fig. 1.

F ig. 3 is a transverse section adjacent the support at the opposite end of the carriage from that shown in Fig. 1.

Fig. 4 is a view looking from the right in Fig. 3.

Figs. 5 and 6 are perspective views showing details of construction.

Fig. 7 is a section substantially on line 77 of Fig.5.

Referring first to Figs 1 and 2,- the numeral 10 designates an upright supporting plate at one endof a platen carriage in which a platen shaft 11 is journaled. The shaft 11 has a ratchet wheellQ, whichmay be rigidly held. thereon and: by means of which line spacing movement is imparted to the platen 13. Apawl supporting bracket l lis pivoted on a. stud l5 which is fitted to the plate 10 by a nut 16. Pivot screw 17 is carried at the upper end of the bracket l l and a pawl 18 is pivotally hKmHtHLlOH the screw 17. The bracket 1 lcarries an offset ear 19 which overlies a spring 20 24: being pivoted on a bolt 25 which extends through the end of an arm 26 lof a bell crank lever 27 by meansofzwhicli the link- E23 isoperated to cause the pawl: 18 to rotate the ratchet 12 for line spacing. The bellcrank 27 is pivotally'mounted on a bracket 28 supported on the'plate 10 by Serial No. 728,907;

screws 29. When the bell crank 27 isoscillated the pawl 18 will be swungabout-the pivot 15 as a center, which gives a; somewhat larger radius than the radius of the ratchet wheel 12. The pawl 18 will, how ever remain in engagement with the ratchet teeth for the limited movement in'iparted thereto and will move upon its pivot 17 a sufficient amount to compensate forthe dif ferencesin radii between the ratchet wheel and: theisupporting bracket for the pawl.

' The are through which the pawl mov-es'is hunted by an adjustable stop screw 30 carried by the plate 10. lVhen the pawl strikes the screw 30 further angular move ment ofthe lever 27 on-its bracket 28 will,

mounted on the plate 10 independent-lyof theplaten shaft so that they will not interfere with the removalof the platenaniil yet will be in position to operate when the platen is replaced. While the platen is be;

mg removed the lever 27is swung into po sition to carry the link 23 'to its rear-most position, th us moving the upper end of the bracket ll out of the path of the platen shaft. To retain the platenin position for operation, a detent hook 32 is providecih which is shown in perspective in Fig The hook 32 is pivoted upon the screw 16 and has a bearing surface 33 forn'ied onan are struck from the axis of the screw The hook 232 may be heldin a plurality of'angular positions by a detent roller 34. shown in Figs. 5 and 7. This roller is movable vertically in slots 36 PI'OVltlGCl 1n the upper end of the hook 32, the roller being pressed downwardly by a spring 38, the ends ofwhich bear beneath a bent-over portion 39 of the hook 82,- while the central portion rests upon the roller 35. A finger-pieceAO engages the ends ofthe roller to facili' tate withdrawing the roller from notches ll, 42 and 43 provided in the edge of the plate 10. The hook 32*is'provided with an offset stopllt positionedin the-path of'a downits forward position as shown in Fig. 2.

When the lever 27 is operated the bracket i l will move away from the stop 44 and permit the pawl 18 to engage the ratchet wheel 12. The amount of movement of the .pawl while in engagement with the teeth of the ratchet wheel will depend upon the position of the stop In the position shown in Fig. 2 sufiicient movement is permitted to provide for single spacing. If, however, the detent roller is brought forward intonotch 42, sufficient movement of the pawl 18 will be permitted to produce double spacing of the paper. When the roller 35 is brought into the notch 41 the contact face 33 of the hook 32 will be moved entirely free from the shaft 11 so that the platen may he lifted from its bearing;

The carriage plate at the opposite end of the carriage from the plate 10 is provided with a notch 51 open at its top to permit removal of the end of the platen shaft journaled in this plate. In order to properly align the platen it is desirable to be able to shift the bearing for the right hand end of the platen shaft, For this reason the bearing slot 51 is made somewhat larger than the diameter of the platen shaft and a supplemental bearing plate 52 is mounted on the plate 50 and provided with a bearing seatfor the shaft 11. The plate 52 is held to the plate 50 by a bolt 53 having an eccentric shoulder 5% journaled in the plate 10. A nut is threaded on the bolt. 53 to lock the shoulder 54: in any position of adjustment to which it may be turned. Since the bolt 53accurately tits in an opening .in the bearing plate 52 it will be apparent that the plate 52 may be shifted v.rtically by rotating the eccentric shoulder 54- on the bolt 53. A locking screw 55 extends through an opening 56 in the plate 50 and is threaded into the upper portion of the plate 52 in order to lock the plate 52 in its various positions of adjustment. The opening 56 is made.

elongated to permit the plate 52 to be swung upon the bolt 53 as a pivot and it is also made sufiiciently wide to permit vertical movement of the plate 52. It will thus be seen that the bearing forthe shaft 11 may be adjusted in any direction to properly align the shaft. In order to retain the shaft in its bearing a hook bracket 57 is pivoted at 58 on the plate 5. This bracket is provided with a bearing face 59 formed on an arc struck from the axis of the pivot 58 to permit the hook to be swung from full to broken line positions in Fig. 3. A stop 60 strikes the edge of the plate 52 to limit the backward movement of the hook. The hook may be provided with a. projection (31 arranged to engage the front edge of the plate 52 to hold the hook in its active position and to engage the depression 53 in the plate 52 to retain the hook in its inactive position.

I claim:

1. The combination with a platen shaft, of an upright plate having an open seat therein for receiving said platen shaft, a ratchet on said platen shaft, a bracket pivotally mounted on said platen carriage plate eccentric to said shaft, a pawl mounted on said bracket for engaging said ratchet wheel, and a limit stop for said pawl, said stop being pivoted on said plate imlependently of said shaft and ar 'anged to limit move ment of said bracket and pawl about the pivotal mounting of said bracket.

2, The combination with a platen carriage shaft, of an uprightcarriage plate having an upwardly open seat therein for receiving said shaft, a ratchet wheel on said shaft, a pawl for operating said ratchet wheel, a bracket for supporting said pawl, a pivotal support for said bracket mounted on said plate below said platen shaft seat, and a stop mounted on said pivotal support for controlling the movement of said pawl.

The combination with a platen shaft, of a platen carriage plate having an open seat therein, ratchet mechanism for rotatiiu said platen shaft, a lever for operating said 'atchet mechanism, a detent pivoted on said plate for retaining said shaft in said seat, and a stop connected with said detent for limiting the movement of said ratchet mech anism and thus limit the range of n'u'ivement of said lever.

l. The combination with a platen and a platen shaft, of a platen carriage plate having an open seat therein for receiving said shaft, a bracket pivoted on said plate cccentric to said shaft, a ratchet wheel mounted on said shaft, a pawl carried by said bracket for operating said ratchet wheel,

a detent pivoted on said plate concentric.

with the pivot for said bracket, and a stop connected with said detent for limiting the movement of said pawl.

5. The combination with a platen and a platen shaft, of a support having an open seat therein for said shaft, ratchet mechanism for rotating said shaft, an adjustable stop for controlling the movement of said ratchet mechanism, a detent for retaining said shaft in said seat, and a common support for said detent and stop pivoted on said platen support.

6. The combination with a platen shaft, of a support having an open seat for said shaft, ratchet mechanism for rotating said shaft, a stop for controlling the movement of said lilf:

ratchet mechanism, means for holding said stop in adjusted positions, a detent for retaining said shaft in said seat, said detent being movable with said stop and arranged to hold said shaft in said seat for the adjusted positions of said stop but movable into an additional position to permit removal of said shaft from said seat, said stop holding means comprising a spring held member for engaging spaced openings in said support, and a finger piece connected with said detent and stop and engaging said spring held member to release said spring held member and shift said detent and stop.

7. The combination with a platen shaft, of spaced supports therefor having open seats to permit removal of said shaft therefrom, and an adjustable bearing mounted on one of said supports to facilitate alignment of said platen shaft, said bearing comprising a plate having a shiftable pivotal support, and means for securing said plate in differ ent positions of adjustment.

8. The combination with a platen shaft, of a pair of supporting plates for said shaft, one of said plates having an opening therein of greater diameter than said shaft and having a supplemental bearing plate adjustably mounted thereon having an opening therein arranged to fit said shaft and fix the position of the axis thereof to facilitate alignment of said shaft and means for fixing said supplemental bearing plate in different positions of adjustment.

9. The combination with a platen shaft, of a pair of spaced bearing plates having open seats therein, one of said plates having a supplemental bearing plate pivotally mounted thereon, the pivotal mounting of said plate being provided with means for adjusting said plate transversely of the axis thereof.

10. The combination with a platen and a platen shaft, of spaced bearing plates therefor, one of said plates having an open seat therein of greater diameter than said shaft, a supplemental bearing plate adjacent said open seat, an eccentric pivot for said plate, and means for locking said plate in adjusted positions.

11. The combination with a platen and a platen shaft, of a pair of spaced bearing plates having open seats therein for receiv ing said shaft, one of said plates having a supplemental bearing plate secured thereto and adjustable thereon for alignment, and a detent pivotally mounted on said supplemental plate.

12. The combination with a platen and a platen shaft, of a pair of spaced bearing plates having open seats therein, a supplemental bearing plate secured to one of said first-mentioned bearing plates, an eccentric pivot for said supplemental bearing plate, means for locking said supplemental bearing plate in adjusted positions, and a detent for retaining said shaft in said supplemental bearing plate, said detent being pivoted on said supplemental bearing plate to move into and out of retaining position.

In testimony whereof I have signed my name to this specification on this 17th day of July, A. D. 1924.

OTTO A. HOKANSON. 

